This invention relates to a crimp ring fitting for connection to plastic or composite piping and the like.
The invention has been developed primarily for use with polyethylene/aluminium composite piping and will be described hereinafter with reference to this particular use. It will be appreciated, however, that the invention is not limited to this particular field of use.
The principle of crimp ring pressure fittings has been established for many years and these are used extensively on hydraulic hoses and other plastic pipe fittings. However, it has been found that the existing crimp ring systems when used in particular on the composite pipes, tend to leak when subjected to cyclic temperature conditions.
Another disadvantage of existing crimp ring fittings is that the copper crimp ring is often damaged or distorted during transport making on site assembly all the more difficult. Furthermore, there is a tendency for the crimp rings, after crimping, to cut into and damage the pipe, particularly at the leading edge of the ring.
An object of the present invention is to provide a range of fittings which will overcome or at least ameliorate the discussed disadvantages of the prior art.